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  1. #1
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    downsizing a carbon road frame to a 24" wheel youth bike?

    Can I use an standard sized carbon frame, cut all tubes and glue/epoxy it to together for a 24" wheel bike? (consider that the riders weight is only half of an adult). Would I?, should I?, use internal sleeves for the reconnection - or other methods?
    Thanks for any input!

  2. #2
    Senior Member RoboMonkey's Avatar
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    It would probably be possible, but it would be pretty difficult. You would need to figure out how to make the proper geometry for the bike, which will take some planning. You should not need any type of internal sleeve, it should be completely unnecessary and will make the bike heavier. Doing so would also make it difficult to get a result that looks good and is structurally sound. If you have not worked with carbon fiber before, it can pretty difficult to work with.

    If you want to do go ahead and do this I could offer some potentially useful advice, having just done something similar to this with a steel bike frame and also having worked with carbon fiber before.



    This is one option for cuts you can make to the bike. You should note that this plan may cause some probably solvable issues, e.g. brake bridge in the wrong spot, since you are switching wheels size. Cut the bike apart, shorten the down tube and seat tube as necessary. You may need to shorten the head tube. For the next step you have a few options.

    1) Reattach your head tube to the shortened down tube then put in the top tube by shortening it as necessary.

    2) Try to put both the head tube and top tube in at the same time.

    3) Make a second cut to the top tube and discard the carbon seat cluster. Use a piece of seat tube from an aluminum or steel frame for the top part of your seat tube.

    Then you need to reattach the seat stays, which should be fairly easy. You will probably need to get creative when trying to figure out the rear brake bridge/boss and small parts such as cable stops.

  3. #3
    Have bike, will travel Barrettscv's Avatar
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    Why risk failure from bonded sections? The exopy used in CF production is very specialized. The over-the-counter epoxy that is commercially available is not intended for this kind of use.

    Just buy a CF MTB frame for 26" wheels, install a rigid fork, drop bars and road tires.

    This can be had in a 15" size for 26" wheels: http://pedalforce.com/online/product...2f206eef61b961
    2014 Trek DS.1: "Viaggiatore" A do-it-all bike that is waiting in Italy
    2012 Pedal Force CG2: "Secolo Bicicletta" the modern carbon fiber road bike
    2012 Pedal Force CX2: "Carbone CX" the carbon fiber CX bike
    2010 Origin 8 CX 700: "Servizio Grave" Monstercross/29er bike
    1997 Simoncini Special Cyclocross: "Little Simon" lugged Columbus steel CX bike
    1987 Serotta Nova Special X: "Azzurri" The retro Columbus SPX steel road bike

  4. #4
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    Define "over the counter". Typical hardware store Epoxy wouldn't be the best option but there are very many Epoxies available to the general public that are more than adequate for bike building.

  5. #5
    weirdo
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    Oy, tons of complications. If you go cutting and chopping any existing frame, remember that the angle between each tube and the next will be slightly changed by shortening. And think hard about wheel sizes. Could you fit your intended rider on 26 inch wheels? If so, Barrett`s answer will save all the headache. From playing with recumbents, I know that sourcing an exceptable tire and rim combination for any 24 inch wheel can be a huge PITA. If you REALLY want some kind of 24 incher, be sure to check on availablity before you start cutting or buying. It`s almost impossible to find anything other than 507 BMX fatties with a million spoke holes or big money weight weenie 520s with funky lacing and very few tires options. 559 or 451 are much simpler, and 559 keeps you from having to figure out brake mounting. Good luck with your project, whatever you decide.

  6. #6
    coprolite fietsbob's Avatar
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    This will be entertaining ..

  7. #7
    Quirky Grifter LesterOfPuppets's Avatar
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    Just put the kid on some Aluminium. Only $800 for a Pinarello:

    1980ish Free Spirit Sunbird fixed * 1996 Mongoose IBOC Zero-G * 1997 KHS Comp * 1990-ish Scapin * Lemond Buenos Aires Triple

  8. #8
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    i wish i had a bike like that when i was younger. that is pretty sweet.

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